Holding device and method for locking the holding device

ABSTRACT

The invention relates to a holding device  020  for human-medicine or veterinary-medicine applications comprising: a joint between a proximal holding segment  001  and a distal holding segment  017 ; wherein one axially displaceable thrust element  002 ,  016  in each case is arranged in the holding segments  001 ,  017 ; wherein the joint has a tightening bolt, which defines the pivoting and tightening axis, and has deflection elements, by means of which a thrust force, acting relative to the axis, of the proximal thrust element  002  is deflectable to lock the joint onto the tightening axis and to displace the distal thrust element  016 ; and wherein the deflection elements comprise at least one ramp system with a wedge body  008 . The invention further relates to a holding system comprising the specified holding device and a method for locking the joint of the specified holding device  020 .

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. Application No. 16/423,712filed May 28, 2019, which claims priority of German Patent ApplicationNo. 102018112682.4 filed on May 28, 2018, the contents of which areincorporated herein by reference in their entirety.

TECHNOLOGICAL BACKGROUND

The invention relates to a holding device having a lockable jointbetween two holding segments for medical applications, for example forholding or positioning a surgical instrument. The invention furtherrelates to a holding system with the specified holding device and amethod for locking and releasing the joint of the specified holdingdevice.

One-armed or multi-armed holding devices or holding systems for medicalinstruments with passive or active guiding are known. In this case,holding devices or systems for guiding instruments are required inparticular in minimally invasive surgical interventions, in order torelieve a surgeon, assistant or other operator from the tiring work ofholding. Such holding devices can be employed to hold a surgicalinstrument such as a manipulator, an optical aid such as an endoscope, aclamp or the like at its distal end. Furthermore, mechatronic assistancesystems can also be combined with a holding device. In this case, it isimportant that attached devices or systems can be handled simply andthat the holding system enables disruption-free operation. When usinginstruments, it is moreover advantageous to provide the surgeon with alarge number of degrees of freedom.

A manually adjustable holding device is known from CH 645 529, which hastwo arms which are pivotable relative to one another and which areconnected by a central joint in an articulated manner. The arms can belocked at the central joint using a tightening member in the form of ahand lever via displaceable tightening sleeves or sockets. Adisadvantage of this known device is that two hands are generallyrequired to release and lock the holding system. The expenditure offorce for tightening is comparatively high as a result of the frictionlosses in the central joint. There is therefore the need to increase theeffectiveness in the flow of force by reducing the friction losses.

Alongside the relatively high friction losses, a further disadvantage ofthe manually adjustable holding device according to CH 645 529 is thatthe transmission relationship, i.e. the relationship in which the forceand the path are implemented, can only be improved to a limited extentby exchanging tightening sleeves with steeper run-on surfaces. There isnamely the problem that, if the run-on surfaces of a tightening sleeveare configured too steeply, they lead to an excessively largeself-inhibition in the event of locking. For example, in the event ofangles over 70° such a large degree of self-inhibition arises that theholding device can no longer be released after locking.

The aim of the present invention is to overcome the specifieddisadvantages and to provide a holding device which is simple to operateand which can be locked or released without a hand lever or a hand screwon the tightening axis of the joint of the holding device. The holdingdevice should in particular be lockable through pressure or introductionof force from the proximal side on an open proximal arm segment orholding segment.

A further aim of the invention is to improve the effectiveness whendeflecting force in the joint of the holding device. Finally,instruments should remain controllable when the holding device is in areleased position and should not move in an unpredicted manner afterrelease or after assuming the release position.

According to a first aspect of the invention, a holding device forhuman-medicine or veterinary-medicine applications is provided,comprising a joint between a proximal holding segment and a distalholding segment; wherein at least one axially displaceable thrustelement in each case is arranged in the holding segments, wherein thejoint has a tightening bolt, which defines the pivoting and tighteningaxis, and has deflection elements, by means of which a thrust force,acting relative to the axis, of the proximal thrust element isdeflectable to lock the joint onto the tightening axis and to displacethe distal thrust element, and wherein the deflection elements compriseat least one ramp system with a wedge body.

With the aid of the deflection elements comprising a ramp system, thetightening bolt can be displaced by means of the introduction of forcefrom the proximal side such that the holding device can be brought froma released position or release position into a locked position orlocking position. When the holding device is in the release position,the holding segments can be pivoted relative to one another such that adistal connection part or an attachable instrument is brought into adesired position. The joint of the holding device can then be locked bymeans of the tightening bolt and the holding segments can thus be fixedin the adjusted position.

In the locking process, the at least one axially displaceable proximalthrust element serves to introduce force proximally, while the at leastone axial distal thrust element is displaceable outwards away from thejoint in order to apply force distally. The force deflected by 90° bythe tightening axis in the direction of the distal thrust element can inturn be used to fix or lock a distal connection part or instrument andthus support a surgeon or other operator.

The force can advantageously be introduced proximally via the proximalthrust element, so that manual locking by means of a tightening lever atthe central joint of the holding device is no longer required.

Friction losses can be reduced through the use of a ramp system with awedge body, which preferably has inclined wedge surfaces, on both sidesand the effectiveness can be improved up to threefold compared toconventional force transmission mechanisms which use neither a wedgebody nor a sliding body.

According to a further aspect of the invention, the at least one rampsystem comprises a base plate which is penetrated by the tightening boltand which has at least one base ramp surface, and a mating plate whichis firmly connected to the tightening bolt and which has at least onemating ramp surface, wherein the wedge body which is acted on by forceis displaceable between the ramp surfaces and is configured to move themating plate relative to the base plate supported on a housing of thejoint, and thus to deflect the force by 90°.

The tightening bolt penetrates the base plate and the at least one rampsurface of the base plate faces an allocatable wedge surface of thewedge body. This design contributes to an optimisation of the spacerequired for the ramp system in the central joint of the holding device.During its displacement, the wedge body is displaceable bothperpendicular to the tightening axis and axially relative to thetightening axis. The component of the displacement path in the axialdirection is limited on one side by the base plate supported on thehousing, such that the axial displacement from the release position intothe locking position takes place in the direction of the movable matingplate, in order to move this together with the tightening bolt for thepurpose of locking.

According to a further aspect of the invention, the component, which isdirected perpendicular to the tightening axis, of the displacement pathof the wedge body between the release position and the locking positionis definable by the length of a central elongated hole of the wedgebody.

The elongated hole forms a through-aperture of the wedge body for thetightening bolt, so that the wedge body forms a substantially ovalhollow cylinder, the base surfaces or annular surfaces of which eachhave one or two opposing wedge surfaces. The elongated hole isconfigured such that it enables a displacement of the wedge body bothperpendicularly and axially relative to the tightening bolt. Dependingon the size of the length or breadth of the elongated hole, thedisplacement movement of the wedge body 008 can take place with playwith respect to the tightening bolt 010 or can be conducted partlythrough at least one wall of the elongated hole. The ends of theelongated hole of the wedge body can in this case adopt a stoppingfunction and/or a guiding function, in order to limit the displacementperpendicular to the tightening axis and/or to guide the wedge bodyalong the tightening axis. A possible friction in the displacementmovement between at least one of the walls of the elongated hole of thewedge body and the tightening bolt should be kept low through theconfiguration of relatively small contact surfaces, in order to enable alow-friction lateral movement of the wedge body on the tightening bolt.

According to a further aspect of the invention, at least one base rampsurface and the at least one mating ramp surface engage one another bythe assignable wedge surfaces of the wedge body in each case via atleast one sliding body.

Through the additional use of sliding bodies, the friction can besignificantly decreased between the respective interacting slidingpartners, i.e. the wedge surfaces and assignable ramp surfaces.

According to a further aspect of the invention, the sliding bodies arerolling bodies in the form of spheres, cylinder rollers or barrelrollers.

In this manner, the friction between the interacting surfaces can bereduced to as small a degree as possible. Particularly advantageous inthis case are barrel rollers, with the surface shell having a convexconfiguration in each case. These barrel rollers not only have a smallerbearing surface compared to cylinder rollers, but rather also enableautomatic centring on arch-shaped or curve-shaped ramp or wedgesurfaces.

According to a further aspect of the invention, the base ramp and/or themating ramp each have two at least sectionally cylinder-segment-shapedrecesses, which each have a track surface curved towards the respectivesliding body as a ramp surface.

In this manner it is possible to provide geometric relationships andautomatic centring surfaces which are favourable to the sliding body, inorder to promote low-friction and reliable operation of the ramp system.Not only the ramp surfaces, but also the wedge surfaces which interactwith them, should have tracks which are arched or curved in such a wayas to enable the surfaces to slide on one another with low friction. Theuse of sliding or rolling bodies in curved or arched tracks of theinteracting surfaces can in this case achieve a significant reduction infriction compared to conventional linear bearings.

According to a further aspect of the invention, the displacement of thedistal thrust element can be used for the frictional locking of a distalconnection part and/or a medical instrument.

In this manner, a medical instrument such as a surgical instrument oroptical aid or the like can be held by the holding device via aconnection part or directly. In order to suit different demands invarious surgical scenarios, the length of the holding segments and theholding force can be varied. In this case, relatively short holdingdevices having a length of approximately 15 cm to 20 cm length perholding segment should be envisaged if relatively high holding forces ofat least 3 kg, preferably 5 kg, are to be provided.

According to a further aspect of the invention, the distal connectionpart is a hand joint that can be coupled to a handle which has at leastone actuation element in order to optionally lock or release the joint.

With the aid of a distal handle and in particular the actuation element,the surgeon or another operator can easily, i.e. with only one hand,bring about the locking or releasing of the holding device.

According to a further aspect of the invention, the housing of the jointis configured in two parts and the ramp system is arranged in theproximal and/or distal housing half.

Providing the ramp system in the proximal side of the joint housing isparticularly advantageous if high forces are necessary to lock thecentral joint. In the case of this arrangement of the ramp system, theproximally introduced force can be strengthened approximately threefoldcompared to conventional tightening mechanisms without a wedge body andthe path is reduced to one third. Through the ramp system, relativelyshort displacement paths can cause very high clamping or locking forcesto be conducted onto the central joint. In this manner it can be ensuredthat a locking of the joint takes place reliably and that both housinghalves are pressed onto one another with a high force.

Depending on the force/path relationships desired, a further ramp systemwith a wedge body and sliding bodies can be arranged in the distalhousing half as an alternative to or in addition to the arrangement inthe proximal housing half.

According to a further aspect of the invention, the holding segments canbe pivoted relative to one another via the joint by a pivot angle of upto 340°.

Limiting the rotation around the joint main axis to 340° is inparticular advantageous, if a cable is guided from the first to thesecond holding segment. In this manner it is advantageously possible toprevent technical malfunctions or breaking of a cable attached to theholding device.

The limiting of the pivotability to a maximum of 340° can be realised bymeans of an anti-rotation pin and a suitable circumferential groove withstops which are each arranged in a housing half of the central joint ofthe holding device. The stops are formed as radially running stopsurfaces in the circumferential groove or respectively at the end of apartly annular circumferential groove and can limit the rotating angleto the specified 340°, which gives a dead angle of 20°. Dead angles ofat least 20° are to be preferred here, as these can be produced morerobustly and therefore have an advantageous effect on the lifespan ofthe holding device.

According to a further aspect of the invention, the deflection elementsfurther comprise a ramp socket which has a curved ramp surface for asliding body, wherein the ramp socket is rotatably connected to thetightening bolt and is displaceable by displacing the relative locationof the tightening bolt along the tightening axis and is engaged with athrust element via the sliding body in order to deflect force.

In this way, the ramp system can be combined with a ramp socket. This isadvantageous if significantly less force is meant to be conducted intoor out of one housing half than is meant to be conducted into or out ofthe other housing half. For example, the ramp socket can be arranged inthe distal housing half if significantly less force is required for theclamping of a distal connection part than for the clamping of the jointof the holding device.

According to a further aspect of the invention, the thrust elements areconfigured as one-part or multi-part thrust rods.

In other words, the thrust elements can either be configured in onepiece or consist of separate parts. One or two thrust elements thusserve as thrust rods or so-called pressure-rams and can for example bepushed loosely into the respective open holding segments and can thus beexchanged simply when necessary. The individual thrust elements and theremaining parts of the holding device are suitable for machine cleaningand disinfection and steam sterilisation in autoclaving.

According to a further aspect of the invention, the thrust rod end whichinteracts with the sliding body of the ramp socket has a ramp surface.

Advantageously, that end of the distal thrust rod which is close to thejoint has a ramp surface, through the angle of which, together with theangle of the ramp socket, it is possible to determine the relationshipin which the force and the path are implemented. The loosely usablethrust rods with ramp surfaces, which are also called ramp rams, cansimply be taken out of the holding segment and be replaced by a ramp ramwith a different angle depending on requirements.

According to a further aspect of the invention, the proximal housinghalf comprises the ramp system and the distal housing half comprises theramp socket with a sliding body configured as a cylindrical orbarrel-shaped rolling body.

This is advantageous if significantly less force is required for theclamping of a distal connection part, for example, than for the clampingof the joint of the holding device.

According to a further aspect of the invention, the joint has an end capwhich can be removed from the proximal housing half in order to enable amanual displacement of the relative location of the tightening bolt overthe proximal end of the tightening bolt.

If the end cap is taken off at the joint, it is possible to manuallydisplace the tightening bolt at its proximal end by means of suitabletools without introducing force at the proximal holding segment. In thismanner, the holding device can be set manually and a fine adjustment canbe performed, which are generally carried out by the manufacturer of theholding device or by maintenance personnel.

According to a further aspect of the invention, the tightening bolt has,at the proximal end, a thread for a nut which is configured to manuallydisplace the relative location of the tightening bolt.

This nut can be operated simply with a conventional tool such as ascrewdriver and simplifies necessary setting or maintenance.

According to a further aspect of the invention, the housing of the jointand/or the holding segments have at least one receptacle for springmeans.

The specified spring means can advantageously guarantee a certainresidual inhibition and thus free holding segments of the holding deviceor of joints, which are attached to the distal holding segment, can beprevented from flapping around in an uncontrolled manner.

According to a further aspect of the invention, the proximal holdingsegment can be connected at its proximal end to a clamping device, bymeans of which the thrust element of the proximal holding segment can bedisplaced to lock and release the joint of the holding device.

A spindle drive or the like is provided as a drive unit for the relativedisplacement of the proximal thrust element. These drives allow simplecontrolling of the relative displacement, since it can be actuated bothby one hand and also advantageously by means of a motor.

According to a further aspect of the invention, the holding device andthe clamping device can be connected to one another by means of acoupling device.

The coupling device is configured such that it can rapidly couple theholding device to, or decouple it from, the clamping device. Thecoupling device is in this case configured such that it cannot bereleased while in operation, even if large forces exert an action duringthe operation of the holding device.

According to a further aspect of the invention, a cable is guided from aproximal actuation element at a handle, which is attached to the distalholding segment, along the holding segments, bypassing the joint, and isconnected to a drive unit in order to axially displace the proximalthrust element of the holding device by means of a driveable spindle ofthe clamping device.

In this manner, the cable can be used in order to be able to connect aproximal drive unit for the proximal introduction of force to a distalactuation element. The cable guided along the holding segments generallybypasses the joint of the holding device in a loose loop. In the case ofan embodiment of the holding device without limitation of thepivotability of the holding segments, there is the danger here of thecable twisting or being overloaded and thus of the functionality of thecable being damaged. In order to lastingly protect the cable fromoverloading or breaking, the rotatability of the joint of the holdingdevice or of the holding segments relative to one another to at least340° is to be envisaged when a cable is guided along the holdingsegments.

Furthermore, a method for human-medicine or veterinary-medicineapplications for locking and releasing a joint of a holding devicehaving two holding segments which are pivotable relative to one anotheris provided. The method comprises the following steps: displacing anaxially displaceable thrust element in a proximal holding segment,deflecting the proximal thrust force of the proximal thrust element ontothe tightening axis of the tightening bolt of the joint, in order tolock the joint, and deflecting the tightening force onto the distalthrust element of the distal holding segment, in order to lock a distalconnection part and/or a medical instrument by displacing the distalthrust element away from the tightening axis, wherein the deflectiontakes place by means of deflection elements comprising at least one rampsystem with a wedge body.

BRIEF DESCRIPTION OF THE FIGURES

Further advantages and features of the invention emerge from thefollowing description of exemplary embodiments on the basis of thefigures. In the drawings:

FIG. 1 shows a perspective view of an embodiment of a holding deviceaccording to the invention;

FIG. 2A shows a schematic plan view of a further embodiment of a holdingdevice according to the invention with a housing and a partial sectionalview in the released position;

FIG. 2B shows a schematic plan view of the holding device shown in FIG.2A in the locked position;

FIG. 3A shows a perspective exploded view of a holding device accordingto the invention;

FIG. 3B shows a detailed view of the proximal part of the holding deviceshown in FIG. 3A, comprising a ramp system;

FIG. 4 shows a schematic view of a holding system with a furtherembodiment of the holding device according to the invention; and

FIG. 5 shows a schematic method diagram for the locking of the joint ofthe holding device according to the invention.

The depictions are schematic and are not necessarily true to scale.Furthermore, they do not show all details but rather partly restrictthemselves to the depiction of the details which are significant to theinvention and of further features which facilitate the explanation anddescription of the invention. Identical elements in the various figuresare labelled with identical reference numbers.

DETAILED DESCRIPTION OF THE FIGURES

The perspective view from FIG. 1 shows an embodiment of a holding device020, according to the invention, for human-medicine orveterinary-medicine applications. This holding device 020 consists of aproximal holding segment 001 and a distal holding segment 017, with ajoint 021 connecting the proximal and distal holding segment 017. Thejoint 021 is depicted in a simplified manner, i.e. without a housing,and shows the significant components required for conducting force ordeflecting force.

The two holding segments 001 and 017 are pivotably borne by means of thelockable joint 021. The ramp system has a base plate 005 penetrated by atightening bolt 010. The mating plate 009 is likewise penetrated by thetightening bolt 010, but, in contrast to the base plate 005, is firmlyconnected to the tightening bolt 010. Both the base plate 005 and themating plate 009 have at least one ramp surface (29, 25), which interactwith the wedge surfaces 028 of a wedge body 008. For this purpose, thewedge body 008 is arranged between the base plate 005 and the matingplate 009.

The wedge body 008 is configured as a hollow cylinder and has at its twobase surfaces at least one wedge surface 028, which on one side issituated opposite the at least one base ramp surface 025 and which onthe other side is also assignable to the at least one mating rampsurface 029. The ramp surfaces 025 and 029 engage with the assignablewedge surfaces 028 of the wedge body 008 via sliding bodies 011.

The tightening bolt 010 has at its proximal end a thread, which is notshown here, for a nut 012, by means of which it is possible to manuallydisplace the relative location of the tightening bolt 010 for adjustmentor maintenance of the holding devices. As a general rule, thisadjustment possibility with the nut 012 is not used for the normaloperation of the holding device, since the application of force to lockthe joint 21 takes place on the side of the tubular proximal holdingsegment 001.

The distal end of the tightening bolt 010 is not visible in FIG. 1 ,because it is arranged in a ramp socket 007. The ramp socket 007 engagesthe thrust element (not shown in FIG. 1 ), which runs axially in theholding segment 017, via a sliding body 013. The holding segment 017 hasat its end a thread, in order to be able to be connected to the distalhousing half (not shown here).

FIG. 2A shows a schematic plan view of the holding device 020, in whichthe joint 021 and the ends of the holding segments 001 and 017 which areclose to the joint are shown in a partial sectional view and, inaddition, the two housing halves 003, 014 of the joint 21 are shown.FIG. 2A shows in the partial sectional view that the housing of thejoint 021 is configured in two parts. In this case, the proximal housinghalf 014 has the ramp system and the distal housing half 003 has theramp socket 007.

The partial sectional view of the distal holding segment 017 shows thatthe holding segment 017 and the distal housing half 003 are connectedvia a thread. Furthermore, the partial sectional view shows that twoaxially displaceable thrust elements 015 and 016 are arranged in theholding segment 017. The ramp socket 007 engages the thrust element 015via the sliding body 013. The thrust element 015 has ramp surface 024which is curved relative to the sliding body 013. The thusfriction-optimised ramp surface 024 of the thrust element 015 or rampram 015 forms the frictional surface with the sliding body 013. On theother side of the sliding body 013 there is arranged a ramp surface 027of the ramp socket 007. In order to support automatic centring in theramp tracks, the sliding body 13 is preferably configured as rollingbodies in the form of barrel rollers.

Further sliding bodies 011 are located in the ramp system in theproximal housing half 014. The base ramp 005 and mating ramp 009 eachhave sectionally circular-segment-shaped recesses which each have atrack surface curved towards the respective sliding body 011. The curvedtracks likewise serve to automatically centre the sliding bodies 011. Byusing the sliding or rolling bodies in the form of barrel rollers, it ispossible to reduce the friction, and to support automatic centring onarched tracks.

In the depicted release position or released position of the holdingdevice, the sliding bods 011 are arranged at the proximal ends of theramp surfaces and the wedge body 008 is substantially perpendicular tothe tightening axis. Through the displacement of the thrust element 002in the distal direction, the wedge body 008 can be displaced bothdistally and axially. A possible displacement or a displacement pathfrom the shown release position of the thrust element 002 in the distaldirection is indicated by the arrow 022.

In the shown released position or release position, the two housinghalves 003 and 014 are movable relative to one another, around thetightening axis. The holding segments 001 and 017 are thus also movablerelative to one another around a large pivot angle. The cylindrical pinor securing pin 004 limits the pivotability to a range of preferably340° and thus prevents an endless rotation of the holding segments 001,017 relative to one another.

A limitation of the pivotability is advantageous if a cable is guidedalong from the first to the second holding segment and if this does notincur damage from overloading as a result of the restrictedrotatability. If no guiding of cable along the holding device isenvisaged, but rather a different type of signal transmission such asradio control, it is possible to dispense with the mechanical limitationof the cylindrical pin 004 and an infinite rotatability of the holdingsegments 001, 017 relative to one another is made possible.

The end cap 006 closes the access to the nut 012 and the proximal end ofthe tightening bolt 010. If the end cap 006 is taken off at the joint021, it is possible to manually displace the tightening bolt 010 at itsproximal end by means of suitable tools without applying force at theproximal holding segment. The adjusting takes place by means of ascrewdriver or the like, for example. The manual adjustment is generallyonly envisaged prior to the first entry into operation and for latermaintenance, if necessary. In this case it is advantageous if it isenvisaged that the adjustment is only permitted to take place withoutany load, i.e. when the tightening bolt 010 is released. The distal endof the tightening bolt 010 is generally located under the cover 006after the holding device 020 has been supplied to the user. This isintended to prevent the user from independently altering the settingrequired for operation.

If the thrust element 002 is displaced in the distal direction inaccordance with the arrow 022, both the joint 021 and the distal medicalinstrument, which is operatively connected via the thrust elements 015and 016, can be jointly locked. This is carried out by means of thetightening bolt 010 arranged perpendicular to the holding segments 001and 017. Its mode of operation shall be explained hereafter withreference to FIG. 2B.

FIG. 2B depicts the locked position or locking position, with identicalelements being identified using the same reference numbers. By applyingforce at the proximal side of the holding segment 001, the thrustelement 002 has been displaced into the locking position in direction ofthe central joint 021, so that the wedge body 008 has moved between theramp 005 and the mating ramp 009 out of the release position into thelocking position. When force is applied, the wedge body 008 is movedsuch that it pushes respectively away from the housing and from one ofthe mating ramp plates 009 via the sliding body 011. In this case, themating ramp 009 is firmly connected by the tightening screw 010.

The displacement path of the wedge body 008 from the release position tothe locking position has both a component perpendicular to thetightening axis and along the tightening axis. By means of the wedgebody 008, the proximal force introduced by the thrust element 002 can bedeflected by 90° into the tightening axis, in order to thus clamp thejoint 021. In the locking position, a proximal side of the wedge body008 rests on the base plate, while the distal inclined end of the wedgebody 008 can come to a stop on the distal housing wall of the housinghalf 014, this distal housing wall running parallel to the tighteningaxis. The wedge body 008 thus assumes the inclined position shown inFIG. 2B with respect to the tightening axis. The wedge body 008 can inthis case advantageously be used in order that the resultingcounter-forces in the locking process during the lateral deflection offorce can be directly introduced into the housing.

The introduced force can additionally be deflected by 90° by means ofthe ramp socket 007, the ramp socket 007 being rotatably connected tothe tightening bolt 010. In order to get into the locking positionshown, the ramp socket 007 has been displaced together with thetightening bolt 010 along the tightening axis in the proximal or axialdirection (arrow 23). The arrow 23 indicates the axial displacement pathof the tightening bolt 010 from the release position to the lockingposition.

The diverted force is transmitted, via the ramp ram 015 or thrustelement 015 with ramp surface 024, onto the distal thrust element 016,in order, through the outward displacement of the thrust element 016, tobe able to lock ajoint or medical instrument attached thereto. Throughthe use of curved ramp surfaces and sliding bodies 013, the deflectionof force can be performed with relatively little friction and, throughthe distal displacement generated, downstream joints connected to thethrust elements 015 or 016 can be locked.

FIG. 3A shows an exploded view of an embodiment of the presentinvention. Here, it is possible to view the two joint halves 003 and014, and the elements associated therewith, separately. The proximalright joint half 014 has the ramp system with the wedge body 008, whilethe distal joint half 003 substantially has a ramp socket 007. A slidingdisc 030 is arranged between the housing halves 003 and 014. A diamondcarbon disc is preferably used in order to allow the joint 021 to rotatewith low friction. The rotatability is limited to preferably 340° bymeans of the anti-rotation pin 004 interacting with a circumferentialgroove (not shown) running in the distal housing half. Thecircumferential groove has radially running stop surfaces or the likefor the limitation.

On the proximal joint side with the ramp system, a proximal force can bestrengthened approximately threefold compared to conventional lockingmechanisms, and in this case the path can be reduced to one third. Thisis particularly advantageous, because in this manner both housing halvescan be pressed onto one another with a high force. On the distal side,on the left side here in FIG. 3A, the force of the tightening axis isthen in turn deflected by 90° in the distal direction. In the shownembodiment, this deflection is performed by a ramp socket 007, which isconnected operatively connected to the thrust element 015 via thesliding body 013.

The shown embodiment of the holding device shows two principles for thetransmission of force. On the one hand, this embodiment of the holdingdevice 020 has, on the proximal side, the combination of sliding bodies011 or rolling bodies with a wedge body 008. On the other hand, asliding body 013 in connection with a ramp socket 007 is provided on theside of the distal housing half 003. Depending on the desired force/pathrelationships, these alternatives can be combined with one another asdesired. For example, as an alternative to the ramp socket 007, a secondwedge body 008 with a ramp system which interacts therewith can bearranged in the distal housing half part 003.

FIG. 3B shows solely the proximal housing half 014 and the associatedcomponents, in order to illustrate details. The base plate 005 isconfigured as a substantially oval hollow cylinder with a circularthrough-hole. The proximal base area of the base plate 005 has opposingrecesses which are in the shape of parabolic segments and which havecurved tracks as base ramp surfaces 025. Ramp surfaces or tracks curvedin this manner are likewise realised by the wedge surfaces 028 in thecase of the wedge body 008.

The wedge body 008 is likewise configured as a hollow cylinder, the basesurfaces of which have said curved wedge surfaces 028. FIG. 3Badditionally shows that the through-hole of the wedge body 008 isconfigured as an elongated hole (026), in order to enable a displacementpath of the wedge body 008 both axially and perpendicularly to thetightening axis. Finally, the two wedge surfaces 028 facing the matingplate 009 interact with two mating ramp surfaces 029 of the mating plate009 via the sliding body 011. The mating ramp surfaces 029 also havecurved tracks, like the wedge surfaces 028.

It is advantageous to provide the ramp system in the right or proximalside of the joint housing, as shown in FIG. 3B, since high forces arenecessary here to clamp the central joint. In this manner it can beensured that a locking of the joint takes place reliably. Through theramp system, small paths can cause very high clamping or locking forcesto be conducted onto the central joint. As shown in FIG. 3B, the rollingbodies 011 run in arched and curved tracks to reduce friction and centreautomatically. This is advantageous compared to conventional linearbearings and can optimise costs and installation space.

FIG. 3B shows that the thrust element 002 has, at its proximal end, agroove for spring means. Through the use of spring means, apredeterminable residual inhibition can be guaranteed and free holdingsegments of the holding device or of joints, which are attached to thedistal holding segment, can be prevented from flapping around. Inoperation, the thrust element 002 is plugged at its distal side into theholding segment 001 or the open arm stump and at its proximal side intoa coupling device 300 which is illustrated in the following FIG. 4 .

FIG. 4 shows a holding system with a holding device 20 according to theinvention. At its proximal end, the holding device 20 is connected to aclamping device 100 via a coupling device 300. The base column 101 islocated at the base of the holding system. This base column or holdingsegment 101 is compatible with all existing and commercially customaryclamping units 105, so that it can be securely clamped on an operatingtable. For example, the base column or the holding segment 101 may havea diameter of approximately 16 mm. Depending on a particularly largeload capacity, larger diameters up to a maximum of 2 cm can also beprovided. The clamping device 100 has a housing 150. For pivotability ofthe holding segment or base column 101 there is located between thehousing of the clamping device 100 and the holding segment 001 a joint152 which, due to the holding system or holding arm distally attached tothe clamping device 100, can also be called a shoulder joint.

The fastening point of the clamping unit 105 for the first holdingsegment 101 is arranged in the proximal region of the clamping device100. The proximal region can be located close to the floor or anoperating table. The holding system can alternatively beceiling-supported as opposed to an operating-table-supported system. Thedistal region of the holding system is the region which is remote fromthe proximal region. A holding device 20 in the form of a holding arm,with an upper arm and lower arm respectively, is attached to the distalside of the clamping device through a coupling device 300. The attachedholding device 20 comprises two holding segments 001 and 017, which arepivotably connected to one another by a central joint 21.

A handle 019 is attached to the distal holding segment 017. A medicalinstrument, for example, can be attached to the free end of the handle019 or holding system. For this purpose, the distal end of the handle019 has a coupling unit 170. This coupling unit 170 can preferably beconfigured as a rapid-coupling unit such as the known KSLOCK interface.Various medical instruments such as microscissors, forceps, tweezers,punches or the like can be attached to such an autoclavablerapid-coupling unit 170. Accessories for the operation can also beprovided, which can be attached to the rapid-coupling unit 170. Thus, ahand rest, for example, can be coupled via the rapid-coupling unit 170.With such a hand rest, the surgeons can keep a steady hand duringsurgical interventions lasting several hours.

Alongside the connection to the hand joint 018, which is preferablyconfigured as a ball joint, and the rapid-coupling unit 170, the handlehas an actuation element 169. The drive unit 160 of the clamping device100 can be activated by the distal actuation element 169. The controlsignal for the activation or actuation of the depicted drive spindle 110can be conducted to the drive unit 160 via the cable 168. The cable 168is guided partly along the holding segments 017 and 001. The cable isguided, with some play, between the proximal holding segment 001 and thedistal holding segment 017, so that the central joint 21 can movefreely. The rotatability of the joint is advantageously limited to 340°to protect the cable.

When the cable is guided to the proximal end of the holding segment 001,it enters into the bolt element 301. The introduction of the cable intothe bolt element 301 of the coupling device enables the control signalsto be passed through to the drive unit 160 via the coupling device 300.The coupling device 300 has inside it suitable contact elements, inorder to further conduct the signal, conducted via the cable, to thedrive control unit 160. As an alternative to cable-guided activation,radio-controlled triggering of the clamping device 100 is alsoconceivable.

In the example depicted, the drive unit 160 includes, for the spindle110, an electric motor 161 with a gear mechanism 162. The power issupplied to the drive unit 160 by a battery 163. The battery 163 isarranged in the battery shaft 164 and is controlled via the batterycontrol unit 165. A drive control unit 166, as well as a switching logic167, is furthermore located in the housing. The spindle 110 can bedriven by means of the gear mechanism 162 of the electric motor 161.

The layout of the thrust elements, holding segments and joints of theholding system conforms to the forces to be conducted and the parts orinstruments to be attached. The maximum reach of the holding system andat the same time the highest stress is achieved when the arm is extendedhorizontally. In this position, the holding system according to theinvention can achieve a holding force between at least 3 kg and 5 kg.Example reaches for the entire holding system are between 55 cm and 71cm. For applications in sterile surroundings, it is necessary tosterilise the holding device 020 and connection parts. Parts of theholding system which are not intended for sterilisation, such as thecoupling device and clamping device, can be covered with a suitablesterile cover or drape.

FIG. 5 shows the significant method steps for locking a joint of aholding device according to the present invention. The first method stepcomprises displacing at least one axially displaceable thrust element002 in a proximal holding segment 001 of the holding device 020. Thesecond method step comprises deflecting the proximal thrust force of theproximal thrust element 002 by means of at least one ramp system with awedge body 008 for locking the joint 021 of the holding device 020. Inthe further method step 203, the deflection of the tightening force ontothe at least one distal thrust element 015, 016 of the distal holdingsegment 017 takes place to lock a distal connection part and/or amedical instrument. In the aforementioned method, high forces forclamping the joint are advantageously attained with small paths. If theholding device 020 is to be brought from the locking position into therelease position, the proximal thrust element 002 can be brought backinto the starting position for this purpose.

List of reference numbers 001 proximal holding segment 002 proximalthrust element 003 distal housing half of the joint 004 securing pin 005base ramp plate 006 end cap 007 ramp socket 008 wedge body 009 matingplate with mating ramp surfaces 010 tightening bolt 011 sliding body ofthe ramp system 013 sliding body of the ramp socket 015 thrust elementwith ramp surface 016 (distal) thrust element 017 (distal) holdingsegment 018 hand joint 019 handle 020 holding device 021 joint 022 axiallongitudinal movement in the distal direction 023 axial movement alongthe tightening axis in the proximal direction 024 ramp surface of thedistal thrust element or ramp ram 025 base ramp surface 026 elongatedhole in the wedge body 027 ramp surface of the ramp socket 028 wedgesurface 029 mating ramp surface 030 disc 031 groove for spring means 100clamping device 101 holding segment or base column 105 clamping unit 110spindle 150 housing of the clamping device 152 joint, base joint 160drive unit 161 electric motor 162 gear mechanism 163 battery 164 batteryshaft 165 battery control unit 166 drive control unit 167 switchinglogic 168 cable 169 actuation element 170 coupling unit for distalconnection part and/or an instrument 201 method step: displacement of aproximal thrust element 202 method step: deflection of the proximalthrust force for locking 203 method step: locking of a distal connectionpart or a medical instrument 300 coupling device 301 bolt element 303coupling groove flank 325 coupling actuator

1. A method for locking and releasing a joint of a holding device havingtwo holding segments which are pivotable relative to one another, themethod comprising the following steps: displacing at least one axiallydisplaceable thrust element in a proximal holding segment; deflectingthe proximal thrust force of the proximal thrust element onto thetightening axis of the tightening bolt of the joint, in order to lockthe joint; and deflecting the tightening force onto the at least onedistal thrust element of the distal holding segment, in order to lock adistal connection part and/or a medical instrument by displacing thedistal thrust element away from the tightening axis; wherein thedeflection takes place by deflection elements including at least oneramp system with a wedge body.
 2. The method according to claim 1,wherein the at least one ramp system includes: a base plate which ispenetrated by a tightening bolt and which has at least one base rampsurface, and a mating plate, which is firmly connected to the tighteningbolt and which has at least one mating ramp surface; and displacing thewedge body which is acted on by force between the ramp surfaces andmoving the mating plate in the direction of the tightening axis relativeto the base plate supported on a housing of the joint, and thus todeflect the force by 90 degrees.
 3. The method according to claim 1,wherein the component, which is directed perpendicular to the tighteningaxis, of the displacement path of the wedge body between the releaseposition and the locking position is definable by the length of acentral elongated hole of the wedge body.
 4. The method according toclaim 2, providing a sliding body and engaging at least one base rampsurface and at least one mating ramp surface to each other by the wedgesurfaces of the wedge body via the sliding body.
 5. The method accordingto claim 4, wherein the sliding bodies are rolling bodies in the form ofspheres, cylinder rollers or barrel rollers.
 6. The method according toclaim 5, wherein the base ramp and/or the mating ramp each have two atleast sectionally cylinder-segment-shaped recesses, which each have atrack surface curved towards the respective sliding body as a rampsurface.
 7. The method according to claim 1, frictionally locking adistal connection part and/or a medical instrument by displacing atleast one distal thrust element.
 8. The method according to claim 6,providing a handle having an actuation element and wherein the distalconnection part is a hand joint that can be coupled to the handle, andwherein the actuation element is configured to lock or release thejoint.
 9. The method according to claim 7, wherein the housing of thejoint is configured in two parts and the ramp system is arranged in theproximal and/or distal housing half.
 10. The method according to claim1, wherein the holding segments can be pivoted relative to one anothervia the joint by a pivot angle of up to 340°.
 11. The method accordingto claim 1, wherein the deflection elements further comprise a rampsocket which has a curved ramp surface for a sliding body, wherein theramp socket is rotatably connected to the tightening bolt and isdisplaceable by displacing the relative location of the tightening boltalong the tightening axis and is engaged with a thrust element via thesliding body in order to deflect force.
 12. The method according toclaim 1, wherein the thrust elements are configured as one-part ormulti-part thrust rods.
 13. The method according to claim 11, whereinthe thrust element which interacts with the sliding body of the rampsocket has a ramp surface.
 14. The method according to claim 13, whereinthe proximal housing half comprises the ramp system and the distalhousing half comprises the ramp socket with a sliding body configured asa cylindrical or barrel-shaped rolling body.
 15. The method according toclaim 9, wherein the joint has an end cap which can be removed from theproximal housing half in order to enable a manual displacement of therelative location of the tightening bolt over the proximal end of thetightening bolt.
 16. The method according to claim 1, wherein thetightening bolt has, at the proximal end, a thread for a nut which isconfigured to manually displace the relative location of the tighteningbolt.
 17. The method according to claim 1, wherein the housing of the joint and/or the holding segments has at least one receptacle for springmeans.
 18. The method according to claim 1, wherein the proximal holdingsegment can be connected at its proximal end to a clamping device, bywhich the thrust element of the proximal holding segment can bedisplaced to lock and release the joint of the holding device.
 19. Themethod according to claim 18, wherein the holding device and theclamping device can be connected to one another by a coupling device.20. The method according to claim 18, wherein a cable is guided from aproximal actuation element at a handle, which can be attached to thedistal holding segment, along the holding segments, bypassing the joint,and is connected to a drive unit in order to axially displace theproximal thrust element of the holding device by a driveable spindle ofthe clamping device.